Question
Biology Question on Principles of Inheritance and Variation
What is the percentage of children being a carrier of haemophilia if their mother is a carrier and their father is a normal man?
A
(A) 25%
B
(B) 50%
C
(C) 75%
D
(D) 100%
Answer
(A) 25%
Explanation
Solution
Explanation:
The percentage of children being a carrier of haemophilia if their mother is a carrier and their father is a normal man is 25% because the gametes formed by mother are X and Xh while the gametes formed by father are X and Y. The genotype of the offspring obtained would be XY, XX, XXh and XhY. Thus 50% of children are normal, 25% are carriers of haemophilia and 25% are haemophilic (only son).Hence, the correct option is (A).